Preparation and properties of non-solvent type and waterborne epoxy resins containing liquefied wood

• Main Authors: Jeun-Yan Lam, 林俊延
• Other Authors: 李文昭
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/23397142994356901013

碩士 === 國立中興大學 === 森林學系所 === 103 === In this study, bisphenol A type epoxy resins were synthesized by reacting epichlorohydrin and bisphenol A with different molar ratios and reaction times. Cryptomeria japonica Don. (Japanese cedar) were liquefied in a mixture of phenol/bisphenol A. The liquefied products were used as raw materials to prepare a biomass containing epoxy resin. The blended epoxy resins were prepared by mixing two types epoxy resin with different weight ratios. Furthermore, the emulsifiers that contained both epoxide group and hydroxyl group were synthesized by the mixture of bisphenol A and different molecular weight [poly(ethylene glycol); PEG] with various molar ratios. The feasibility of waterborne epoxy resins that prepared by adding the emulsifier and processed via phase inversion method was investigated. The results show that epoxy resins prepared with lower epichlorohydrin/bisphenol A molar ratio had higher average molecular weight, viscosity, and epoxy equivalent weight. The exothermic peak appeared at DSC thermal analysis shifted to higher temperature with less reaction heat. In addition, the weight retention, bending strength, storage modulus and phase transition temperature of cured resins decreased but the heat resistance increased. However, the properties of epoxy resins did not be influenced by the reaction time. Blended resins containing liquefied wood have less reactivity, but the cured resin had higher heat resistance at temperature higher than 300°C. Waterborne epoxy resins prepared with the emulsifier that had a higher PEG molecular weight, and had the PEG/epoxy molar ratio closed to 1/1 had a better emulsion stability. DSC and TGA analysis shows that the bottom layer resin for waterborne epoxy resins prepared with different conditions had the similar curing behavior and had the same thermal resistance for cured resins. However, moldings made with waterborne epoxy resin that prepared with the emulsifier that synthesized with PEG having the molecular weight of 4000 and the PEG/epoxy molar ratio of 1/0.8 had better mechanical properties. Comparison between the weight ratios of blended epoxy resin, moldings made with the waterborne resin that had more content of biomass containing epoxy resin had lower mechanical properties. However, they had better heat resistance at temperature over 300°C.